Thoroughgoing philosophical skepticism undermines liberty by denying that law can be reasonable, and that justice can be known.
Joe Biden believes there is something in the philosophical tradition called an “evolving view of natural law:”
Natural law reasoning must be dynamic, capable of change. Only with expanding conceptions of “due process,” “equal protection,” and rights “reserved to the people” can the development of individual rights and liberties keep pace with the other changes in our country.
Biden deployed this mythical philosophical creature in 1991 when trying to block Justice Clarence Thomas from sitting on the Supreme Court. People interested in ethical theory know that natural law is opposed to relativism and historicism. Contrary to the idea that justice is reducible to national will and its history, natural law is the theory that right and wrong do not change because what it means to be human does not change. It is the claim that reason discerns the moral implications of our most basic desires, determining that certain things must be avoided and others pursued. These moral-bearing inclinations are few, and the obligations linked to them are also few. For this reason, and because our social lives are complex, a natural law theorist acknowledges that these rational obligations must be supplemented by adjudications from positive law. Positive law—human and divine—does change with history. Tastes, mores, and circumstances evolve; deliberative bodies and judiciaries of varied polities craft, revise, and dispense with myriad laws as sensibilities and national conditions change.
Natural law does not change, but human positive law does. (Even divine positive law can change. The Christian God, at least, posits laws which he then later changes—marriage laws, for instance). In natural law reasoning, therefore, there is considerable need for human law to supplement natural law. Thomas Aquinas argues, for instance, that natural law demands murder be punished, and punishment may include the death penalty. However, what punishment is exacted for murder is left to the polities of different lands to determine for themselves. Punishment is set by human law.
Is human law infinitely elastic? No: some positive law determinations might conflict with the unchanging core of rational human nature. If a positive law clashes with those few, socially foundational obligations stemming from this fixed core, that law is unjust. Natural law trumps human law when push comes to shove. Natural law is the measure of the rationality of human law.
This is natural law theory in outline. Joe Biden’s version is mythical and confused. James Carey’s Natural Reason and Natural Law offers an excellent account of natural law. I drew the above outline from it. Carey’s book is not for everyone. But for anyone who wants a genuinely meaty consideration of natural law and who has the patience to dwell on careful distinctions and close reading of texts, this is a very good resource.
Athens and Jerusalem: Strauss on Aquinas
Natural Reason and Natural Law has two distinctive features. First, its focus on Aquinas is complemented by a consideration of one of his most astute critics, Leo Strauss. Born in Prussia in 1899, Strauss taught political thought at the University of Chicago for many years and influenced many American political theorists (now known as Straussians). Carey covers some of Strauss’s students’ criticisms of natural law, too. The other distinctive feature is the inclusion of Martin Heidegger, one of Strauss’s interlocutors (who also happened to be an anti-Semite and National Socialist). Other than Wittgenstein, Heidegger is the most influential 20th-century philosopher. His account of nature, which many scholars find attractive, is a problem for both Aquinas and Strauss.
Aquinas’s natural law attracted Strauss’s interest because of its attempt to give an account of justice that transcends particular political orders. Like Aquinas, Strauss opposed relativism and historicism. However, according to Strauss, Aquinas’s natural law is not the purely philosophical discernment of natural justice that it purports to be. Philosophy is the exercise of autonomous understanding, but natural law is inescapably theological and does not speak “to man as man.” The Catholic Straussian, Father Ernest Fortin, argues that this is so because law requires promulgation; it needs a lawgiver to make the law publicly known. Aquinas has smuggled God into his supposedly rational account of law, just as Strauss contends. Natural law is really piety. To this charge, Carey replies that Aquinas makes promulgation original to reason: As Aquinas argued, “the first common precepts of the law of nature are self-evident to one who possesses natural reason, and do not need to be promulgated.”
In his metaphysical work, Aquinas argued that “no reality lacks its specific operation.” Quarks, gluons, and proteins even display a logic. Our species, homo sapiens, has its “specific operation,” the rational articulation of appetites. Strauss in his 1968 “On Natural Law,” accurately summarizes the Thomistic position: “Man is by nature inclined toward a variety of ends which possess a natural order; they ascend from self-preservation and procreation via life in society toward knowledge of God.”
As Carey explains: “man…could not be what he is without knowing natural law, just as he could not be rational without knowing the principle of non-contradiction.” This is because “reason by its very nature is oriented toward determining both what is and what ought to be.” Oriented to the true and good, reason stipulates “that good is to be done and pursued, and evil avoided.” The goods to be pursued are self-preservation, procreation, society, and knowledge of God. The first two inclinations, being the fundamental principles of natural selection, have had confirmation from Darwin, and primatology confirms the third. Put otherwise, reason identifies in humans’ animal appetites a legal framework: prohibitions against suicide, child abuse, and hatred, along with obligations to self-care, family, and rule of law are all derivable from such appetites. Legislators in all countries mull over laws respecting these themes all the time. As Aquinas says, “law is nothing else than an ordinance of reason for the common good.”
In a letter to Eric Voegelin, Strauss writes that the Greeks show “that truly human life is a life dedicated to science, knowledge, and the search for it,” not deference to divine revelation. Fatefully, contends Strauss, Aquinas inherited both a Greek philosophical tradition and a legacy of Biblical ethics. This blending of Athens and Jerusalem is disastrous, for it not only weds law to “theology and its controversies,” but also obscures the difficulty of moral knowledge and the fraught decisions inevitable in politics. The problem with Thomistic natural law is that it does not take politics seriously enough. For Strauss, the relationship between reason and law is a delicate one: reason must not collapse into national passions but is nevertheless tasked with pragmatic judgements to defend the polity.
In Carey’s presentation, Strauss prefers the Greeks because they understood that there are no “universally valid rules of action” dictated to political actors. This is just as well, for events sometimes require political leaders to make harsh decisions that are incompatible with the rules believed by Aquinas to be implicit in natural law (what he calls the secondary precepts of natural law). For example, Aquinas and Thomistic jurists like Francisco de Vitoria elaborated a theory of just war with protections for innocents. Natural law, counters Strauss, thereby makes nations vulnerable, tying the hands of leaders confronting acute, even existential, events. Decisions, not laws, are sometimes basic.
Heidegger or Aquinas?
But Strauss has two problems. First, Carey argues that Strauss overstates the place of God in Thomas’s natural law reasoning. The obligation respecting a knowledge of God merely posits that the question of God must be addressed by law. Archeology favours Aquinas. An ivory figurine known as the Lion-Man found in Germany and dating to 35,000 years ago is the earliest indisputable work of art so far found. It is also thought to be the first known religious artefact. At a minimum then, the theologico-political problem is inescapable. This means, against Strauss, that a religious pressure always exists on the statesman, curbing his scope of action. The gods will have a say, too.
Strauss’s second problem comes from Heidegger. Heidegger is one of the founding figures of phenomenology. Through his novel approach to experience, Heidegger claims careful attention shows that natural law is not remotely natural. That is, it is no part of original human experience. Like Strauss, Heidegger also returned to the Greeks but proved the better historian. For the Greeks, the world was a harsh battle for recognition: life was a competition for glory. Heidegger writes:
This was clarified through the highest possibility of human Being, as the Greeks formed it, through glory and glorifying… Glory is the repute in which one stands. Heraclitus says, “for the noblest choose one thing above all others: glory, which constantly persists, in contrast to what dies; but the many are sated like cattle.”
Strauss returned to Greece to torpedo Aquinas only to find himself outflanked by Heidegger. As Carey puts it, Heidegger showed the “world as intrinsically non-rational.” The idea of rational nature which Aquinas and Strauss held dear, was, Heidegger argued, just an abstraction crafted by Western philosophy. In fact, what made both philosophy and natural law possible was a decline, an idealization of nature born of theology. Heidegger worries Strauss because his thinking exposes Strauss to be as pietistic as Aquinas. Strauss also appreciated the urgency of the challenge: he was under no illusions about his teacher, writing that Heidegger “explicitly denies the possibility of ethics.” Ethics is not original to a chaotic, violent world or the Greek effort to restrain it through the celebration of struggle and vaunting of the self.
Heidegger or a Thomistic nature kindly displaying a logic discernible by reason and science? There is only one option able to sustain the rule of law. The harmonies described by the thinkers of the Enlightenment—often interpreted as undermining natural law—are in continuity with Aquinas. But Carey ends his book fearful that Strauss, for all his moral earnestness in paring back natural law, exposed justice to the cruelties of ancient and modern strife.